In perfect contrast to another SNP also within the LRRK2 gene, rs34637584, this SNP, rs34778348, is not found in Caucasian populations but is found in Asian populations.

A case-control study of 989 Chinese subjects concluded that the odds ratio for Parkinson's disease was 2.1 for rs34778348(A) carriers (CI: 1.1-3.9, p = 0.014). This SNP was estimated to account for 4% of all Parkinson cases in this population.[PMID 17019612]